Well, we know that such utilities can do more harm than good, so who knows what damage has been done, but if all this utility did was to delete the contents of the Prefetch folder then there is no harm done there.
You looked into it and said to do this. What said to do this?
Did this problem occur before or after you used that utility?
What type of internet connection, and details of your system please.
What anti-virus are you using? We know that some suites like Norton will begin to cause problems when it is passed its renewal date and we haven't renewed the license.
First step, a test. Reboot into the Safe Mode list of options then select "Safe Mode with Networking". Use that for a while but only on well known and trusted web sites and see if the connection disappears or remains stable.
After that, reboot back into Normal Mode then scan for malware so update your anti-virus scanner's definitions and run a full scan with that. When that is done, download, install, update then run full scans with the free versions of Malwarebytes Anti-malware and SUPERAntiSpyware.
Let us know how you get on.
It is worse on IE but even on Chrome my internet keeps shutting down 10-30 mins and keeps doing that over and over. The signal is excellent. I deleted all the files in my prefetch directory. I looked into it and said to do this. So I did, now am worried that maybe they meant XP. The reason why I say this is I took on a 30-day trial utility cleaner and when it was completed it said that from deleting my prefetch files I deleted bootup files and internet log on files. Uugh Please, did I do wrong and if not any suggestions as to how to fix. Thank you.